The Five-hundred-meter Aperture Spherical radio Telescope (FAST) is a Chinese megascience project to build the largest single dish radio telescope in the world. The funding proposal for FAST was approved by the National Development and Reform Commission in July 2007. The FAST foundation was established in December 2008. Construction officially commenced in March 2011, and FAST had first light on 25 September 2016.

FAST aspires to supersede the current world-leading single-dish telescope, Arecibo, with three innovations/advantages:

1) An active surface with more than 4450 adjustable panels to realize pointing and tracking as the world’s largest steerable antenna under 3 GHz;

2) A light-weight cabin driven by 6 cables and servo-motors under closed-loop control up to a precision range of 5 decades;

3) A site of deep Karst depression situated in mountains, which helps shield radio frequency interference (RFI).

The main observables of FAST are pulsars, the 21cm atomic hydrogen hyperfine transition, molecular transitions including masers, and radio continuum. Its unparalleled sensitivity and excellent survey speed should allow astronomers to vastly expand the total volume of knowledge of compact objects, gaseous galaxies, and interstellar medium. The potential discoveries of FAST include thousands of new pulsars, the first pulsar in a spiral galaxy beyond Milky Way, hundreds of thousands of new HI galaxies, dark galaxies that make up part of the so-called missing baryons, the most distant OH mega-masers, new component of the molecular universe, and many more.